Nanostructured networks

Soler-Illia, G.J.A.A. Sanchez, C. Lebeau, B. Patarin, J. Chemical strategies to design textured silica and metal oxide-based organised networks from nanostructured networks to hierarchical structures. Chem. Rev. 2002, 102, 4093. 

Bulk semiconductor nanostructured networks of CdS have been prepared in L and Hi phases [33,34]. The L phase was formed by a polyol amphiphile shown in Fig. 6. This LLC phase was doped with Cd2+ ions and then CdS was precipitated by diffusion of H2S into the gel. This nanocomposite was found to incorporate the amphiphile and metal in alternating layers (Fig. 6), closely resembling the structure of biominerals (e.g., mother of pearl). Similarly, Hi phases were prepared from an oligo(ethylene oxide) oleyl ether amphiphile (Fig. 7) mixed with a solution of Cd2+. Again, H2S was added to precipitate CdS and the resulting composite preserved the hexagonal symmetry (Fig. 7). 

Groups (OR) are silanol alkoxy groups, which react with the active centers of the substrate by reaction with -OH groups and this forms a stable bond. Additional hydrolysis of organosilane oligomers creates a secondary nanostructured network polymer. 

Fig. 33 is a schematic illustration of a porous semiconductor electrode interpenetrated with a redox electrolyte. Two situations are shown the dark equilibrium situation and the situation under constant illumination from the electrolyte side (comparable illustrations for a bulk semiconductor/electrolyte interface are given in Figs. 4 and 5). In the dark at equilibrium, the electron Fermi-level in the porous network, Ep , is equal to the Fermi-level of the redox system Ep,redox = — Ueq) and independent of the spatial co-ordinate x normal to the substrate. If an electrolyte with a sufficiently positive redox potential is chosen, can be located in the middle of the gap, which means that the density of electrons in the nanostructured network is... 

As discussed in section 2, photogenerated holes can readily reach the surface of the nanostructured network and it is assumed that they react with Red generating Ox. If the holes are consumed rapidly, Ep,p will remain close to Ep,redox- In many systems, by contrast, it appears that electrons react much more slowly at the interface than holes. The reason for this kinetic selection of carriers is not clear at present, but it is clearly a prerequisite for the observation of substantial photocurrent efficiencies. If electrons do not react rapidly at the interface, their concentration increases substantially under illumination, so that becomes higher than Ep, edox- Since elec-... 

Figure 8.1 An architectural model (left) and transmission electron micrograph (right) of an aerogel showing the nanostructured network and pore structure. (Left panel reproduced with permission from D. R. Rolison and B. Dunn, J. Mater. Chem. 2001, 11, 963. Copyright 2001 Royal Society of Chemistry. Right panel reproduced with permission from M. L. Anderson et al., Adv. Eng. Mater. 2000, 2, 481. Copyright 2000 Wiley-VCH.)...

Figure 17.7 (A) Cyclic voltammogram of catechol on a platinum electrode. (B) Effect of poly(aniline-co-o-aminophenol) fiber diameter on the electrochemical oxidation of catechol, at a scan rate of 60 mV Average fiber diameter ( ) 70 nm, (2) 90 nm, (3) 100 nm, (4) 107 nm, in a solution consisting of 5 mM catechol and 0.3 M Na2S04 with pH 5.0. (Reprinted with permission from Electrochimica Acta, Poly(aniline-co-o-aminophenol) nanostructured network Electrochemical controllable synthesis and electrocatalysis byShaolin Mu, 51, 17, 3434-3440. Copyright (2006) Elsevier Ltd)...

S.L. Mu, Poly(aniline-co-o-aminophenol) nanostructured network Electrochemical controllable synthesis and electrocatalysis, Electrochim. Acta, 51, 3434—3440 (2006). 

Polymer solar cell Typically the p-type conducting polymer can be applied as hole transporting material, and the mostly used is PEDOTPSS in polymer solar cell. This material has been studied thoroughly and fabricated into one-dimensional nanostructured network... 

Malvankar NS, Mester T, Tuominen MX, Lovley DR. Supercapacitors based on c-type cytochromes using conductive nanostructured networks of living bacteria. ChemPhysChem 2012 13 463-468. 

Alvarez-Lorenzo, C., Puga, A.M., Concheiro, A., 2012. Nanostructures and nanostructured networks for smart drug deUvery. In Biomimetic Approaches for Biomaterials Development. Wiley-VCH Verlag GmbH Co. KGaA. 

Platinum nanostructured networks (PNNs) were prepared via chemical reduction of H2PtCl6 by benzyl alcohol imder microwave irradiation. The networks were micrometer long and consisted of connected secondary nanoparticles, which were actually formed by aggregation of aroimd 3 nm Pt nanocrystals. The formation of the PNN structure was attributed to the collision-induced fusion of Pt nanocrystals due to the cooperative functions of microwave irradiation and benzyl alcohol [150]. Kessler and coworkers reported a one-step synthesis of hydrophilic spherical palladium nanoparticles of imiform size and shape by solvothermal decomposition of Pd(II) acetylacetonate in acetophenone [151]. 

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